The current invention relates to a transformer having an integral cabinet which features an apparatus for latching and locking the doors of the cabinet.
Transformers for commercial and residential electrical service are often mounted on the ground external to the structures they serve. Although such transformers are housed in integrally formed cabinets to deny access to unauthorized personnel, as well as to protect the transformer from the weather, they are vulnerable to tampering by vandals and small children. Doors are provided in such cabinets to allow access to the transformer for installation, maintenance and service. Ensuring that these doors can not be opened by unauthorized personnel is of prime importance in preventing tampering.
In the past, such doors were secured by a three point latch arrangement. The latching and locking devices associated with this prior art arrangement are shown in FIGS. 1 and 2. The first and second latch points were provided by upper and lower rods 112, 113, shown in FIG. 2, which were attached to a cam 110 and which engaged the upper and lower sills (not shown in FIGS. 1 and 2) of the cabinet. As shown in FIG. 1, the cam 110 was attached to the shaft 111 of a vertically extending handle 105. The third latch point was provided by a latch 106 which was attached to a threaded portion 120 of the cam 110 and engaged a flange 107 which extended from an interior barrier 100. The latch 106 was prevented from unlatching by a bolt 108 extending through the door 102 and threaded into the cam 110. The door 101 was retained behind the door 102. A cylinder 104 surrounded the head of the bolt 108 and, along with a padlock 103, prevented the bolt from being removed. The padlock 103 also prevented rotation of the handle 105 by securing a bracket 104 extending from the handle to the cylinder 104. A spring 109 was installed under the head of the bolt to facilitate its removal.
Unfortunately, there was sufficient flexibility in the latching system shown in FIGS. 1 and 2 to allow the latohes to be sprung by applying sufficient outward force to the doors. Such force caused the rods 112, 113 to be bent out of engagement with the sills and latch 106 to be bent out of engagement with the flange 107.
Accordingly, it would be desirable to provide an apparatus for latching and locking the cabinet doors which fasten the doors directly to a structural member of the cabinet so that the latch can not be sprung by merely bending the latching elements.